Presently, there are two postage metering device types: closed systems and open systems. In a closed system, the system functionality is solely dedicated to metering activity. Examples of closed system metering devices, also referred to as postage evidencing devices, include conventional digital and analog (mechanical and electronic) postage meters wherein a dedicated printer is securely coupled to a metering or accounting function. In a closed system, since the printer is securely coupled and dedicated to the meter, printing evidence of postage cannot take place without accounting for the evidence of postage. In an open system, the printer is not dedicated to the metering activity, freeing system functionality for multiple and diverse uses in addition to the metering activity. Examples of open system metering devices include personal computer (PC) based devices with single/multi-tasking operating systems, multi-user applications and digital printers. An open system metering device is a postage evidencing device with a non-dedicated printer that is not securely coupled to a secure accounting module. Open system indicia printed by the non-dedicated printer is made secure by including addressee information in the encrypted evidence of postage printed on the mailpiece for subsequent verification.
Conventional closed system mechanical and electronic postage meters have heretofore secured the link between printing and accounting. The integrity of the physical meter box has been monitored by periodic inspections of the meters. Digital printing postage meters, which are closed system postage meters, typically include a digital printer coupled to a metering (accounting) device, which is referred to herein as a postal security device (PSD). Digital printing postage meters have removed the need for physical inspection by cryptographically securing the link between the accounting and printing mechanisms. In essence, new digital printing postage meters create a secure point to point communication link between the accounting unit and printhead. See, for example, U.S. Pat. No. 4,802,218, issued to Christopher B. Wright et al and now assigned to the assignee of the present invention. An example of a digital printing postage meter with secure printhead communication is the Personal Post Office.TM. manufactured by Pitney Bowes Inc. of Stamford, Conn. An example of a digital printing postage meter in a secure housing is the PostPerfect.TM. also manufactured by Pitney Bowes Inc. of Stamford, Conn.
In even a modest size mailroom it is common that several meters are present. It has been shown that funds can be stored in one central location for batch mailing purposes where evidence of postage payment for batch mail printed at several printers is evidenced through the printing of a statement summarizing the postage for the batch of mail. See U.S. Pat. Nos. 4,760,532 and 4,837,701, each assigned to the assignee of the present invention. However, this scheme has limitations. First, the scheme is limited to batch mail processing without evidencing (franking) postage on each mailpiece. In addition, in large mailrooms it is common for mail to be processed for several different originating zip codes. Since each meter is assigned one originating zip code, meters are frequently moved from one mailing machine to another depending upon the mail processing needs.
In U.S. Pat. No. 4,837,701, a mail processing system is disclosed for processing batch mail utilizing a plurality of work stations, such as inserters. In U.S. Pat. No. 4,760,532, a mail processing system is disclosed for processing batch mail utilizing a single work station. However, in each case postage is evidenced by printing an accounting statement containing information accumulated during the processing of the batch of mailpieces. The accounting statement is a summary of the type and number of mailpieces processed and the amount of postage for the entire batch. Thus, in U.S. Pat. Nos. 4,760,532 and 4,837,701 the postage for each mailpiece is not evidenced on the mailpiece but by the accounting statement that must accompany the batch of mail when deposited with the post. The accounting statement is printed by a printer that is different than the printer used to prepare the mailpieces.
In U.S. Pat. No. 5,682,427, a postage metering system with dedicated and non-dedicated printing means is disclosed. However, in this postage metering system only the non-dedicated printer prints evidence of postage. The dedicated printer is part of a digital postage meter that is coupled to the processor that controls the non-dedicated printer. The digital postage meter is present solely to provide the processor and ultimately the non-dedicated printer with the encrypted information that is printed as evidence of postage. Since addressee information is included in the encrypted information, the non-dedicated printer prints open system evidence of postage.